Kyzysiekmz, yes the Yumeya Cage was designed for the M970-SGS. NOT the M972.
The M972 which is the shadow will defo not fit the Di2 or DA7900.
If you do try it. please remember there is a spacer/washer this needs to be after the bolt has passed through the Plates/sleeve.
Thw spacer will only has a lip this must be facing towards the bolt, which sits into the gove. This stops the plates binding to the mech.
thisisatest, yep I have noticed the offeset of the of the top pulley. However has anyone tried it it with a smaller pulley? I am not sure about the pivot spring you are referring to. There are 4 springs on the Di2. The steeper angle can be adjusted with a screw? no?
maxxevv, yep M972 shadow cages will not fit, not only the linkages but the metal sleeve is different too. However from my pictures.
You can see the Yumeya plates has the same fittings as the DA79xx.
eme999, hmm... you need to see this.. It may shock yo a bit.
This is taken from Nathans long term review. http://range.wordpress.com/2010/03/07/nathans-long-term-shimano-dura-ace-di2-review/